Improved method of quarrying slate



UNITED STATEs PATENT OEEICE.

JOHN

E. \V()()TTEN, 0F OItESSONA, PENNSYLVANIA.

INIPROVED METHOD OF QUARRYING SLATE.

Speelimtien Forming part of Letters Patent No. 58,932, dated October 16, 1866.

'of reference marked thereon.

Myinventior. consists of certain mechanism to bc used for rapidly quarrying slate-rock, in the manner fully described hereinafter, so that the shattering and consequent waste of avait able rock which accompanies the usual mode of quarrying may be prevented.

In order to enable others skilled in the art to which this most nearly appertains to make and use my invention, I will now proceed to describe its construction and operation.

In reference to the accompanying drawings, which form a part of this specitication, Figure l is a side view of my machine for cutting slate-rock; Fig. 2, a plan view Fig. 3, an end view; and Figs. 4, 5, and 6, diagrams illustrating the manner in which the rock is cut by the machine.

A is an oblong frame, which rests on four casters, a a, fitted to the lower ends of verti cal screw-rods B B, which project through the frame, one at each corner of the same. To the upper end of each screw is secured a suitable hand-wheel, b, and round each screw, between a shoulder, c, and the eastern, is coiled a spring, d, for a purpose described hereinafter. In suitable bearings on the frame A turns a shaft, C, at each end of which is a crank, the pin of each of the latter being embraced by oneI end of a rod, c, the other end being connected to the piston-rod ot' a cylinder, D, which is secured to the iframe A, and which is provided with the usuali'valves and ports for the admission and emission of steam or compressed air. To the shaft care secured a fly-wheel, E, and two pulleys, c c. In suitable bearings at the under side of the frame turns a shaft, F, one end of which projects beyond the side of the machine, andjgitojthis projecting' end of the shaft is secured a circular saw, G. 0n the shaft F are two pulleys, t' i, and around each of the latter and around the adjacent pulley c on the shaft C passes an endless belt, m.

Slate-rock is frequently found deposited in such a manner that blocks of it may be split from it in a horizontal or nearly horizontal direction, and where there are natural vertical fissures in the rock within a short distance of each other, large blocks of slate between the tissures may be readily detached by driving wedges into the rock, as shown in Figs. 5 and 6, the natural clefts or fissures being represented at .r a'. W'here, however, these fissures are at such a distance apart that the fracture produced by the wedges will not extend from one fissure to another, blasts are made in order to detach blocks of a proper size for being split and converted into marketable slates. NVhen the rock is displaced 'in this manner it is broken and shattered to such an extent that but a comparatively small portion of the entire mass is detached in a shape available for the purposes required.

In order to avoid this great loss ot material, I employ the above-described machine, which is used in the following manner: Steam or compressed air is conducted through iiexible tubes to the valvechests of the cylinders D D, and the screws b b are so turned as to elevate the frame A until the lower edge of the saw (,l is above the surface of the rock on which the machine rests. The engines are then set in motion, and the frame A is gradually lowered by turning the screws B B. The revo1ving saw is thus brought in contact with the rock, which is cnt away as the saw descends. When a cut of the desired depth has been made, the downward movement of the frame is arrested and the machine is moved in the direction of the arrow, Fig. 1, parallel to the line on which the eut has been made, the saw, as it is brought against the rock, severing the same in the direction of its motion and to the depth to which it has been adjusted.

When a cutof the required length has been made, the frame A is again elevated to the position shown in red lines, Fig. 1, by turning the screw-rods B, and the machine is moved to such a position that another eut may be made parallel to the first, and at such a distance from it that the mass of rock between the two may be readily removed in the manner before described.

As the casters a a are moved over the irregular surface of the rock, the springs d d will permit them to fall or rise slightly without the horizontal position of the frame being matcrially ai'ected.

It is not necessary that the saw should have teeth, as I have found that a circular plate ot' metal with plain edges will operate on the rock with excellent et'fect.

It will be evident without', further description that slate rock may be quarried in the manner and by the appliances above described without that sacricing ot' Yast quantities of available rock which accompanies the usual operation of blasting', and that blocks may be detached with great rapidity and in a shape best adapted for conversion into marketable slates.

It will. also be apparent that the saw erentter maybe secured to a shaft turning in bearin gs or boxes rendered adjustable iu the frame, or the saw-shalt may turn in arms hung,` loosely to the driving,I or crank shaft of the engines, and thusbe rendered adjustable without iuterfering,` with the proper action of the dri\' ing pulleys and belt.

Without confining myself', therefore, to the special construction and arrangement ot' parts herein described, I claim as my invention and desire to secure by Letters Patent- 1. The quarrying` of slate and other like rock by the use of a circular saw or cutter caused to revolve ou a portable and adjustable frame, and arranged for operating on the rock substantially iu the manner described.

L. The combination of the frame A, its adjusting' screwrods with casters ai, its drivingengines, and circular saw (l, the whole being;l arranged and operating,` substantially as and for the purpose herein set forth.

3. The spring d, arranged on cach screw-rod between a collar, d, on the saine and the caster a, substantially as and for the purpose described.

In testimony whereoll l havesigned my naine to this specification in the presence of two subscribing witnesses.

J. E. \\'()()TTEN.

JOHN Wurm, CHARLES E. Fos'rna. 

